MIC1232 Micrel Semiconductor, MIC1232 Datasheet - Page 4

• Manufacturer Part Number: MIC1232
• Description: P Supervisory Circuit
• Manufacturer: Micrel Semiconductor

MIC1232 P Supervisory Circuit
Pin Functions
Pin 1: PBRST - Pushbutton reset input. This input is debounced and can be driven with external logic signals or by
Pin 2: TD - Time delay input. This input selects the timebase used by the watchdog timer. When TD = 0V, the
Pin 3: TOL - Tolerance select input. Selects whether 5% or 10% of V CC is used as the reset threshold voltage.
Pin 4: GND - IC ground pin, 0V reference.
Pin 5: RST - RST is asserted high if either V CC goes below the reset threshold, the watchdog times out or PBRST is
Pin 6: RST - RST is asserted low if either V CC goes below the reset threshold, the watchdog times out or PBRST is
Pin 7: ST - Input to the watchdog timer. If ST does not see a transition from high to low within the watchdog timeout
Pin 8: V CC - Primary supply input, +5V.
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means of a mechanical pushbutton to actively force a reset. All pulses less than 1ms in duration on the
PBRST pin are ignored, whereas, any pulse with a duration of 20ms or greater is guaranteed to cause a
reset.
watchdog timeout period is set to a nominal value of 150ms, when TD = open, the watchdog timeout period is
set to a nominal value of 600ms and when TD = V CC , the watchdog timeout period is 1.2sec nominally.
When TOL = 0V, the 5% tolerance level is selected and when TOL = V CC , a 10% tolerance level is selected.
pulled low for a minimum of 20ms. RST remains asserted for one reset timeout period after V CC exceeds the
reset threshold or after the watchdog times out or after PBRST goes high.
pulled low for a minimum of 20ms. RST remains asserted for one reset timeout period after V CC exceeds the
reset threshold or after the watchdog times out or after PBRST goes high. Open-drain output.
period, RST and RST will be asserted.